Replace sha1sum with jack's gosum and get rid of
vendor-deps.
Also don't compute hash on vendor/ contents.
Instead hash go.sum.
Disable unconvert lint check. It does not
work very well with go mod.
Remove update_vendor_deps once and for all.
Upgrade to go 1.12
Closes: #3919#3630
- Rename get_dev_tools to devtools
- tools and devtools now create a stamp after execution so
that they are not executed twice on the same pipeline
- Add clean target to remove stamps
